Elevation change of the Antarctic ice sheet, 1995-2000, from ERS-2 satellite radar altimetry

Abstract

We analyzed Antarctic ice-sheet elevation change (dH/dt) from 1995 to 2000 using 123 million elevation change measurements from European Remote Sensing 2 ice-mode satellite radar altimeter data covering an area of about 7.2 million km/sup 2/. Almost all drainage basins in east Antarctica had average dH/dt values within /spl plusmn/3.0 cm/year, whereas drainage basins in west Antarctica had substantial spatial variability with average dH/dt values ranging between -11 to +12 cm/year. The east Antarctic ice sheet had a five-year trend of 1/spl plusmn/0.6 cm/year, where 13 out of the 14 basins had either a positive trend or a trend that was not significantly different than zero. The west Antarctic ice sheet had a five-year trend of -3.6/spl plusmn/1.0 cm/year due largely to strong negative trends of around 10 cm/year for basins in Marie Byrd Land along the Pacific sector of the Antarctic coast. The continent as a whole had a five-year dH/dt trend of 0.4/spl plusmn/0.4 cm/year. Finally, time series constructed for the Pine Island, Thwaites, De Vicq, and Land glaciers in west Antarctic showed five-year dH/dt trends from -26 to -135 cm/year that were significantly more negative than the average dH/dt trends in their respective basins. The strongly negative dH/dt values for these coastal glacier outlets are consistent with recently reported results indicating increased basal melting at these glaciers' grounding lines caused by ocean thermal forcing.